√180 + √75? :confused:

You can convert the numbers 180 and 75 to their prime factors, and then combine terms. I woin't do your specific homework problem for you, but here's an example that illustrates what I mean. Consider sqrt(108) + sqrt(147). Break thse numbers down to their prime factors: 108 is equal to 2*2*3*3*3 and 147 = 3*7*7. Hence you have sqrt(2*2*3*3*3)+sqrt(3*7*7). Recall that sqrt(a^2) = a, so this can be simplified as: 2*3*sqrt(3) + 7*sqrt(3). Now you can combine the sqrt(3) terms:

2*3*sqrt(3) + 7*sqrt(3) = (6+7)*sqrt(3) = 13*sqrt(3).

Use this same method on your problem. Post back and let us know what you get.